Examples of symmetry in shapes.

3-rotational symmetry

Symmetric arcades of a portico in the Great Mosque of Kairouan also called the Mosque of Uqba, in Tunisia.

Reflectional Symmetry is a property of certain geometrical objects that appears the same when mirrored or reflected along an axis. This axis has to cross the shape through the middle of that object dividing into equal halves.

In rotational symmetry, the object is identical when it is rotated by a certain amount.

The precise notions of symmetry have various measures and operational definitions. For example, symmetry may be observed

• with respect to the passage of time;
• as a spatial relationship;
• through transformations such as rotation;
• through other kinds of transformations;
• as an aspect of scientific models, language, music and even knowledge itself.